Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
ip22-int.c
Go to the documentation of this file.
1 /*
2  * ip22-int.c: Routines for generic manipulation of the INT[23] ASIC
3  * found on INDY and Indigo2 workstations.
4  *
5  * Copyright (C) 1996 David S. Miller ([email protected])
6  * Copyright (C) 1997, 1998 Ralf Baechle ([email protected])
7  * Copyright (C) 1999 Andrew R. Baker ([email protected])
8  * - Indigo2 changes
9  * - Interrupt handling fixes
10  * Copyright (C) 2001, 2003 Ladislav Michl ([email protected])
11  */
12 #include <linux/types.h>
13 #include <linux/init.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/interrupt.h>
16 #include <linux/ftrace.h>
17 
18 #include <asm/irq_cpu.h>
19 #include <asm/sgi/hpc3.h>
20 #include <asm/sgi/ip22.h>
21 
22 /* So far nothing hangs here */
23 #undef USE_LIO3_IRQ
24 
25 struct sgint_regs *sgint;
26 
27 static char lc0msk_to_irqnr[256];
28 static char lc1msk_to_irqnr[256];
29 static char lc2msk_to_irqnr[256];
30 static char lc3msk_to_irqnr[256];
31 
32 extern int ip22_eisa_init(void);
33 
34 static void enable_local0_irq(struct irq_data *d)
35 {
36  /* don't allow mappable interrupt to be enabled from setup_irq,
37  * we have our own way to do so */
38  if (d->irq != SGI_MAP_0_IRQ)
39  sgint->imask0 |= (1 << (d->irq - SGINT_LOCAL0));
40 }
41 
42 static void disable_local0_irq(struct irq_data *d)
43 {
44  sgint->imask0 &= ~(1 << (d->irq - SGINT_LOCAL0));
45 }
46 
47 static struct irq_chip ip22_local0_irq_type = {
48  .name = "IP22 local 0",
49  .irq_mask = disable_local0_irq,
50  .irq_unmask = enable_local0_irq,
51 };
52 
53 static void enable_local1_irq(struct irq_data *d)
54 {
55  /* don't allow mappable interrupt to be enabled from setup_irq,
56  * we have our own way to do so */
57  if (d->irq != SGI_MAP_1_IRQ)
58  sgint->imask1 |= (1 << (d->irq - SGINT_LOCAL1));
59 }
60 
61 static void disable_local1_irq(struct irq_data *d)
62 {
63  sgint->imask1 &= ~(1 << (d->irq - SGINT_LOCAL1));
64 }
65 
66 static struct irq_chip ip22_local1_irq_type = {
67  .name = "IP22 local 1",
68  .irq_mask = disable_local1_irq,
69  .irq_unmask = enable_local1_irq,
70 };
71 
72 static void enable_local2_irq(struct irq_data *d)
73 {
74  sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
75  sgint->cmeimask0 |= (1 << (d->irq - SGINT_LOCAL2));
76 }
77 
78 static void disable_local2_irq(struct irq_data *d)
79 {
80  sgint->cmeimask0 &= ~(1 << (d->irq - SGINT_LOCAL2));
81  if (!sgint->cmeimask0)
82  sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
83 }
84 
85 static struct irq_chip ip22_local2_irq_type = {
86  .name = "IP22 local 2",
87  .irq_mask = disable_local2_irq,
88  .irq_unmask = enable_local2_irq,
89 };
90 
91 static void enable_local3_irq(struct irq_data *d)
92 {
93  sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
94  sgint->cmeimask1 |= (1 << (d->irq - SGINT_LOCAL3));
95 }
96 
97 static void disable_local3_irq(struct irq_data *d)
98 {
99  sgint->cmeimask1 &= ~(1 << (d->irq - SGINT_LOCAL3));
100  if (!sgint->cmeimask1)
101  sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
102 }
103 
104 static struct irq_chip ip22_local3_irq_type = {
105  .name = "IP22 local 3",
106  .irq_mask = disable_local3_irq,
107  .irq_unmask = enable_local3_irq,
108 };
109 
110 static void indy_local0_irqdispatch(void)
111 {
112  u8 mask = sgint->istat0 & sgint->imask0;
113  u8 mask2;
114  int irq;
115 
116  if (mask & SGINT_ISTAT0_LIO2) {
117  mask2 = sgint->vmeistat & sgint->cmeimask0;
118  irq = lc2msk_to_irqnr[mask2];
119  } else
120  irq = lc0msk_to_irqnr[mask];
121 
122  /* if irq == 0, then the interrupt has already been cleared */
123  if (irq)
124  do_IRQ(irq);
125 }
126 
127 static void indy_local1_irqdispatch(void)
128 {
129  u8 mask = sgint->istat1 & sgint->imask1;
130  u8 mask2;
131  int irq;
132 
133  if (mask & SGINT_ISTAT1_LIO3) {
134  mask2 = sgint->vmeistat & sgint->cmeimask1;
135  irq = lc3msk_to_irqnr[mask2];
136  } else
137  irq = lc1msk_to_irqnr[mask];
138 
139  /* if irq == 0, then the interrupt has already been cleared */
140  if (irq)
141  do_IRQ(irq);
142 }
143 
144 extern void ip22_be_interrupt(int irq);
145 
146 static void __irq_entry indy_buserror_irq(void)
147 {
148  int irq = SGI_BUSERR_IRQ;
149 
150  irq_enter();
151  kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
152  ip22_be_interrupt(irq);
153  irq_exit();
154 }
155 
156 static struct irqaction local0_cascade = {
157  .handler = no_action,
158  .flags = IRQF_NO_THREAD,
159  .name = "local0 cascade",
160 };
161 
162 static struct irqaction local1_cascade = {
163  .handler = no_action,
164  .flags = IRQF_NO_THREAD,
165  .name = "local1 cascade",
166 };
167 
168 static struct irqaction buserr = {
169  .handler = no_action,
170  .flags = IRQF_NO_THREAD,
171  .name = "Bus Error",
172 };
173 
174 static struct irqaction map0_cascade = {
175  .handler = no_action,
176  .flags = IRQF_NO_THREAD,
177  .name = "mapable0 cascade",
178 };
179 
180 #ifdef USE_LIO3_IRQ
181 static struct irqaction map1_cascade = {
182  .handler = no_action,
183  .flags = IRQF_NO_THREAD,
184  .name = "mapable1 cascade",
185 };
186 #define SGI_INTERRUPTS SGINT_END
187 #else
188 #define SGI_INTERRUPTS SGINT_LOCAL3
189 #endif
190 
191 extern void indy_8254timer_irq(void);
192 
193 /*
194  * IRQs on the INDY look basically (barring software IRQs which we don't use
195  * at all) like:
196  *
197  * MIPS IRQ Source
198  * -------- ------
199  * 0 Software (ignored)
200  * 1 Software (ignored)
201  * 2 Local IRQ level zero
202  * 3 Local IRQ level one
203  * 4 8254 Timer zero
204  * 5 8254 Timer one
205  * 6 Bus Error
206  * 7 R4k timer (what we use)
207  *
208  * We handle the IRQ according to _our_ priority which is:
209  *
210  * Highest ---- R4k Timer
211  * Local IRQ zero
212  * Local IRQ one
213  * Bus Error
214  * 8254 Timer zero
215  * Lowest ---- 8254 Timer one
216  *
217  * then we just return, if multiple IRQs are pending then we will just take
218  * another exception, big deal.
219  */
220 
221 asmlinkage void plat_irq_dispatch(void)
222 {
223  unsigned int pending = read_c0_status() & read_c0_cause();
224 
225  /*
226  * First we check for r4k counter/timer IRQ.
227  */
228  if (pending & CAUSEF_IP7)
229  do_IRQ(SGI_TIMER_IRQ);
230  else if (pending & CAUSEF_IP2)
231  indy_local0_irqdispatch();
232  else if (pending & CAUSEF_IP3)
233  indy_local1_irqdispatch();
234  else if (pending & CAUSEF_IP6)
235  indy_buserror_irq();
236  else if (pending & (CAUSEF_IP4 | CAUSEF_IP5))
237  indy_8254timer_irq();
238 }
239 
240 void __init arch_init_irq(void)
241 {
242  int i;
243 
244  /* Init local mask --> irq tables. */
245  for (i = 0; i < 256; i++) {
246  if (i & 0x80) {
247  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 7;
248  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 7;
249  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 7;
250  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 7;
251  } else if (i & 0x40) {
252  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 6;
253  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 6;
254  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 6;
255  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 6;
256  } else if (i & 0x20) {
257  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 5;
258  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 5;
259  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 5;
260  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 5;
261  } else if (i & 0x10) {
262  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 4;
263  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 4;
264  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 4;
265  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 4;
266  } else if (i & 0x08) {
267  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 3;
268  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 3;
269  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 3;
270  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 3;
271  } else if (i & 0x04) {
272  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 2;
273  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 2;
274  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 2;
275  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 2;
276  } else if (i & 0x02) {
277  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 1;
278  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 1;
279  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 1;
280  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 1;
281  } else if (i & 0x01) {
282  lc0msk_to_irqnr[i] = SGINT_LOCAL0 + 0;
283  lc1msk_to_irqnr[i] = SGINT_LOCAL1 + 0;
284  lc2msk_to_irqnr[i] = SGINT_LOCAL2 + 0;
285  lc3msk_to_irqnr[i] = SGINT_LOCAL3 + 0;
286  } else {
287  lc0msk_to_irqnr[i] = 0;
288  lc1msk_to_irqnr[i] = 0;
289  lc2msk_to_irqnr[i] = 0;
290  lc3msk_to_irqnr[i] = 0;
291  }
292  }
293 
294  /* Mask out all interrupts. */
295  sgint->imask0 = 0;
296  sgint->imask1 = 0;
297  sgint->cmeimask0 = 0;
298  sgint->cmeimask1 = 0;
299 
300  /* init CPU irqs */
301  mips_cpu_irq_init();
302 
303  for (i = SGINT_LOCAL0; i < SGI_INTERRUPTS; i++) {
304  struct irq_chip *handler;
305 
306  if (i < SGINT_LOCAL1)
307  handler = &ip22_local0_irq_type;
308  else if (i < SGINT_LOCAL2)
309  handler = &ip22_local1_irq_type;
310  else if (i < SGINT_LOCAL3)
311  handler = &ip22_local2_irq_type;
312  else
313  handler = &ip22_local3_irq_type;
314 
315  irq_set_chip_and_handler(i, handler, handle_level_irq);
316  }
317 
318  /* vector handler. this register the IRQ as non-sharable */
319  setup_irq(SGI_LOCAL_0_IRQ, &local0_cascade);
320  setup_irq(SGI_LOCAL_1_IRQ, &local1_cascade);
321  setup_irq(SGI_BUSERR_IRQ, &buserr);
322 
323  /* cascade in cascade. i love Indy ;-) */
324  setup_irq(SGI_MAP_0_IRQ, &map0_cascade);
325 #ifdef USE_LIO3_IRQ
326  setup_irq(SGI_MAP_1_IRQ, &map1_cascade);
327 #endif
328 
329 #ifdef CONFIG_EISA
330  if (ip22_is_fullhouse()) /* Only Indigo-2 has EISA stuff */
331  ip22_eisa_init();
332 #endif
333 }
Generated on Thu Jan 10 2013 13:12:12 for Linux Kernel by   doxygen 1.8.2